Mercury emissions trends over five decades in a technology-based global inventory.

Accurate emissions estimation is essential for the impact evaluation and for designing effective mitigation actions. The Emissions Database for Global Atmospheric Research (EDGAR) provides independent estimates of speciated mercury emissions by sector at global and national levels, and emissions gridmaps of 0.1 x 0.1 degree resolution for the period 1970-2022. The trend analysis shows that in this period mercury emissions increased by 123% reaching the level of 1863 tonnes in 2022. At sectorial level, the emissions from chlor-alkali, which had a great share in 1970 (14%), decreased by 96% whereas the emissions from cement production, which had a share of 4% in 1970 increased by 421% contributing to the total global emissions in 2022 by 10%. Special attention is given to the artisanal small-scale gold mining (ASGM) sector due to its significant share of 16% in 1970 and of 47% in 2022; we will provide an insight on the uncertainty related to the methodology and data availability, the drivers leading to an increase of 567%, and on global spatial distribution of mercury emissions.

The impact of increases in fuel consumption (303%) together with the implementation of mitigation technologies on the levels of mercury emissions is investigated for power generation sector, which showed an increase of 100% in the period 1970-2022. We developed a “no end-of-pipe (EoP) ex-post scenario” to analyse the impact of the mitigation of mercury emissions by end-of-pipe abatement measures in the power generation sector. Figure 1 illustrates the global mercury emissions from fuel combustion in power generation over five decades together with the levels of emissions in the “no end-of-pipe (EoP) ex-post scenario”. The mitigation measures implementation in this sector accounted for 437 tonnes of avoided mercury emissions in 2020.

The trend analysis will be extended to look at the regional particularities focusing on the ten IPCC Continental Regions. The relevant findings will be presented together with the uncertainties for each sector.

Figure 1. Mercury emissions from fuel combustion in power generation: a) mercury emissions over five decades are represented in green and the emissions from no end-of-pipe (EoP) ex-post scenario are represented in blue; the bars on the graph illustrate the fuel share by type, b) emissions shares by sector in 2020 for the three continents for which the contribution from power generation sector is important.